The present invention falls within the scope of production of cementitious articles with light transparency properties. In particular, the object of the present invention is a multilayer panel with light transparency and thermal insulation properties.
There has been an increase in the demand for cementitious articles with light transparency properties in recent years. In one particularly preferred embodiment, these are in the form of the panels based on cementitious mortar.
As is known, there are different methods for producing these panels. In general, these methods provide for light transparent elements to be arranged inside a formwork into which the cementitious mortar is subsequently casted to obtain a cementitious item within which the elements of light transparent material remain incorporated. This manufactured item is subsequently finished so as to obtain the desired panel. Example embodiments of these panels are, for example, described, in patent applications EP 2376718, M12013A000790, M12013A000486 filed in the name of the Applicant.
It has however been found that these panels do not have acceptable acoustic and thermal insulation capacities or, in any case, such as to make them widely usable. Indeed their use is currently limited to applications in which thermal and/or acoustic insulation is not a determining aspect. It follows that in all those cases in which there is a real need to thermally and/or acoustically insulate two environments, the use of these panels is not even taken into consideration, thus renouncing from the beginning to the light transmission capacity offered by them. Panels containing layers of plastic foam have been proposed so as to increase the thermal and acoustic insulation properties. Patent application EP 1970179 B1, for example, shows a method for producing a panel that provides for a layer of insulating material provided with openings for the passage of light transparent elements to be arranged so as to substantially define an inner structure of the panel. This structure is inserted into a formwork into which the cementitious mortar is subsequently cast, arranged on two opposite sides of the plastic foam layer. A multilayer panel is thus obtained wherein the plastic foam constitutes a substantially central layer.
The process described in EP1970179 therefore aims to reduce the thermal conductivity of the panel. It is however clear that such a solution cannot be satisfactory as it is too complex and difficult to achieve. In particular, the preparation step of the layer of insulating material appears inconvenient and difficult to produce at competitive costs. In is observed that the method described in EP1970179 in principle determines an increase in panel thickness so as to reduce the thermal conductivity thereof. As is known, the increase in thickness does not lead to a directly proportional increase of the thermal insulation. Therefore this solution does not appear advantageous beyond a certain value of thickness.
From the above considerations there emerges a need to provide alternative technical solutions that allow the light transmission capacity offered by the cementitious items at issue to be more effectively exploited.
The main object of the present invention is to provide a new panel with light transparency properties that allows the drawbacks of the prior art to be overcome. In the context of this object a first main aim is to provide a panel with improved thermal insulation characteristics without renouncing the cability to transmit light radiation through the panel itself. Another aim of the present invention is to provide a panel that is reliable and easy to produce at competitive costs.
This object and these aims are achieved by means of a multilayer panel with light transparency properties, as indicated in claim 1. The panel according to the invention maintains a light transparency as all the layers have this property. The presence of at least one defined interspace between the two outermost portions of the panel gives the panel a larger thermal insulation capacity. The interspace indeed constitutes a thermal conduction barrier between the two outermost surfaces of the panel. The presence of one or interspaces inside the panel also advantageously allows the acoustic insulation to be increased with respect to traditional solutions. The panel according to the invention is also easy to assemble at extremely competitive costs.
Further characteristics and advantages will become clear from the following detailed description of the method of producing the cementitious items according to the present invention, illustrated by way of a non-limiting example by means of the accompanying drawings, wherein:
The same numbers and the same reference letters in the drawings identify the same elements or components.
The present invention therefore relates to a multilayer panel with light transparency properties and with improved thermal insulation properties Panel 1,1′,1″,1′″,111,111′ according to the invention comprises a first outer surface 21 and a second outer face 22 opposite to said first outer surface 21. For the purposes of the present invention, the outer surfaces 21,22 substantially indicate the two opposing faces of the panel 1,1′,1″,1′″,111,111′ having greater extension.
The two outer surfaces 21,22 are preferably parallel to each other. Panel 1,1′,1″,1′″,111,111′ according to the invention comprises a first portion 4 outermost that extends between the first outer surface 21 and a first inner surface 21′ that is preferably parallel to the first outer surface 21. This first portion 4 has light transparency properties, i.e. properties such that light can be transmitted from the first outer surface 21 to the first inner surface 21′ and vice versa. The first portion 4 comprises at least one first layer 10 made of composite material based on cementitious mortar that defines at least the first outer surface 21 of the panel 1,1′,1″,1′″,111,111′. The first layer 10 comprises first inner portions 55 that pass through the layer itself through the entire thickness thereof evaluated according to a reference direction 300 orthogonal to the first outer surface 21 and to the second outer surface 22.
Panel 1,1′,1″,1′″,111,111′ according to the invention moreover comprises a second outermost portion 5 that extends between the second outer surface 22 and a second inner surface 22′ that is preferably parallel to the second outer surface 22. Analogously to the first portion 4, the second portion 5 also has transparency properties such as to allow light transmission from the second outer surface 22 to the second inner surface 22′ and vice versa.
The second portion 5 also comprises a first layer 20 made of composite material based on cementitious mortar that defines at least the second outer surface 22 of the panel 1,1′,1″,1′″,111,111′. The first layer 20 of the second portion 5 has a substantially analogous configuration to that of the first layer 10 of the first portion 4. In detail, the first layer 20 of the second portion 5 comprises second inner portions 155 that pass through the layer itself layer through entire thickness thereof, again evaluated according to the reference direction 300 indicated above. The panel 1,1′,1″,1′″,111,111′ according to the invention also comprises a third portion 6 (hereinafter also referred to as “central portion 6”) comprised between the first portion 4 and the second portion 5. This central portion 6 comprises spacer means that are configured to define at least a first interspace 11 between the first portion 4 and the second portion 5 of the panel 1. For the purposes of the present invention, the term “interspace” generically indicates a gap for air or other gas that is, in any case, interposed between the first portion 4 and the second portion 5.
In the context of the present invention, the thickness of an interspace is evaluated as the extension along the above-defined reference direction 300. Similarly, the thickness of portions 4,5,6 of the panel 11,1″,1′″,111,111′, as well as the thickness of any other layers constituting the portions themselves, is also evaluated according to this reference direction 300.
The presence of one or more interspaces defined between the outermost portions 4,5 of the panel 1,1′,1″,1′″,111,111′ gives thermal insulation properties. Indeed, the transmission of heat between first portion 4 and second portion 5 can only occur by means of irradiation and/or by means of convection. When the panel 1,1′,1″,1′″,111,111′ is used as a separation structure between two environments at a different temperature, each interspace defined within the central portion 6, as a matter of fact, constitutes a thermal barrier that advantageously limits dispersion through the panel itself.
For each of the two outermost portions 4,5, the corresponding first layer 10,20 can advantageously have an analogous structure to the one shown in
With reference to the structure of
For the purposes of optimising light transmission through panel 1,1′,1″,1′″,111,111′, the above-indicated two layers 10,20 are configured in such a way that each of the inner portions 55 of the first layer 10 of the first portion 4 is aligned with a corresponding inner portion 155 of the first layer 20 of the second portion 20 according to the reference direction 300.
The first inner surface 21′ and the second inner surface 22′ are therefore mutually facing and are separated by an interspace 11, which thickness, measured according to the reference direction 300, substantially coincides with the distance between the inner surfaces 21′, 22′ themselves. It follows that the thickness of the interspace 11 substantially coincides with that of the third portion 6.
In the solution illustrated in
The elements of the peripheral frame 44 can be made of aluminium or alternatively of a material having high thermal insulation (i.e. with low thermal conductivity) that can, for example, be the material commercially known as TGIO. These elements have a thickness in a range normally between 6 mm and 32 mm. Moreover, these can be in tubular in shape or be internally hollow. In this case, the hollows of the tubular elements can advantageously contain dehydrating salts useful for preventing condensation phenomena inside the interspace externally defined by the elements themselves.
From the above, it emerges that interspace 11 is therefore defined by a volume delimited by the inner surfaces 21′,22′ of the two portions 4,5 of the panel 1 and by the inner sides 45 of the elements of the frame 44. The interspace 11 is externally sealed by means of a sealing substance. For the purposes of the present invention, and in the case in which the interspace 11 is defined between two surfaces made of cementitious material (such as in the embodiment shown in
With specific reference to the exploded view of
In this embodiment, air, which thus acts as an insulating means between the first portion 4 and the second portion 5, is preferably provided within the interspace 11.
The first interspace 11 is defined between the first inner surface 21′ of the first portion 4 and the first face 30′ of the central layer 30, while the second interspace 12 is defined between the second inner surface 22′ of the second portion 5 and the second face 30″ of the central layer 30 opposite to the first face 30′. Preferably the two interspaces 11, 12 have the same thickness. In this regard, the first portion 4 and the second portion 5 also have the same thickness so that panel 1′ has an overall symmetrical configuration with respect to a central plane of symmetry 301 (indicated in
With specific reference to the exploded view of
The methods used to glue the elements of the two peripheral frames 54,44 and, where necessary, to seal the two interspaces 11,12 preferably correspond to those described in the comment to the first embodiment. Reference should therefore be made to the corresponding parts of the above-reported description.
The thickness of the central layer 30 is established as a function of the desired level of thermal insulation to be obtained for panel 1 and/or of the type of material used. The central layer 30 could, for example, be made of a glass selected from the group consisting of float base glass, extra-clear glass, low emissivity multilayer glass comprising at least one thermal insulating layer, multilayer glass comprising one reflecting insulating layer, multilayer glass comprising a safety glass layer coupled with a low emissivity glass, tempered glass, decorative glass, screen printed glass and possible combinations thereof. Alternatively, the central layer 30 could be made of a hardening and light transparent thermoplastic material preferably selected from the group consisting of PMMA, PET, PETg, SAN, PS and PVC.
The first layer 10 of the first portion 4 and the first layer 20 of the second portion 5 respectively define the first outer surface 21 and the second outer surface 22 of the panel 1″. The second layer 41 of the first portion 4 and the second layer 42 of the second portion 5 respectively define the first inner surface 21′ and the second inner surface 22′ of the panel 1″. The outermost layers 10,20 of the two portions 4,5 of the panel 1″ have a structure preferably corresponding to the one shown in
According to a first possible embodiment, the intermediate layer 51 of the first portion 4 and the intermediate layer 52 of the second portion 5 are made of a light transparent thermoplastic material which, once subjected to heating, above its temperature, takes on adhesive properties so as to produce adhesion between the two layers 10-41 and 20-42 between which it is interposed. Preferably, said intermediate layers 51,52 are made of a thermoplastic material selected from the group consisting of polyvinyl butyral (PVB), thermoplastic polyurethane (TPU), ethylene vinyl acetate (EVA) and mixtures thereof. In this regard, it has been observed that in the case in which the innermost layers 41,42 are made of glass then the use of PVB as material for the intermediate layers 51,52 appears particularly advantageous.
According to a possible embodiment, the material constituting the intermediate layers 51,52 can have a different shade of colour than the material constituting the inner portions 55,155 of the layers made of cementitious material that form the first layer 10 of the first portion 4 and the first layer 20 of the second portion 5. By varying the shade of colour of the intermediate layers 51,52 with respect to that of the inner portions 55,155 it is advantageously possible to obtain different visual effects without intervening on the manufacturing method of the first layer 10,20 of the outermost portions 4,5 of the panel.
Each of the outermost portions 4,5 of the panel 1″ is produced by means of a method that provides for a first step wherein the panel 1 is assembled by superimposing and pressing together the layers 10-51-41 and 20-52-42 that define the portion itself. In the case of the first portion 4 for example, the intermediate layer 51 is interposed between the first layer 10 and the second layer 41. During assembly of the first portion 4, the intermediate layer 51 is therefore pressed between the first layer 10 and the second layer 41. This operation therefore determines a first cohesion between the layers 10-51-41 that is subsequently reinforced by means of a heating step with a controlled temperature and pressure. Indeed, once assembled, the first portion 4 is heated, under pre-established pressure conditions, at a temperature that is greater than the glass transition temperature of the thermoplastic material that forms the intermediate layer 51 until adhesion of the second layer 41 with the first layer 10 is achieved. In other words, following heating at a regulated pressure, the intermediate layer 51 in fact acts as an adhesive layer between the first layer 10 and the second layer 41, while however maintaining the light transparency characteristics. Light transmission between the outer face 21 and the inner face 21′ of the first portion 4 is thus guaranteed. At the same time, the presence of the second layer 41 significantly increases the thermal insulation capacity. The second portion 5 of the panel 1″ is assembled in an analogous manner to the first portion 4.
According to an alternative embodiment, the intermediate layer 51 of the first portion 4 and the intermediate layer 52 of the second portion 5 can be constituted by a film or transparent sheet made of a double-adhesive material or even by a layer of single-component or two-component transparent glue (epoxy or polyurethane glue for example) or solvent based glue (methacrylic glue for example). In this case therefore, the first portion 4 and the second portion 5 can be assembled by means of a substantially “cold” process that does not require pre-established temperature and pressure conditions.
In the solution illustrated in
It is observed that in this fourth embodiment, given the materials provided for the innermost layers 41,42 of the two portions 4,5, the elements of the peripheral frame 44 can be glued to the corresponding inner surfaces 21′,22″ by means of butyl glue. The interspace 11 is preferably sealed according to the methods previously set out above, to which reference should be made. Under these conditions, i.e. following sealing, the interspace 11 can be advantageously filled with a specific chemically inert noble gas, such as for example argon, krypton, xenon or mixtures of these gases. This solution allows for a further increase in the thermal insulation capacity of the panel 1″.
With specific reference to
In a similar way to what has already described above, the interspaces 11,12 are in this case also defined by means of spacer means comprising a first plurality of spacer elements that define a first peripheral frame 44, and a second plurality of spacer elements that define a second peripheral frame 54 according to principles analogous to those already indicated above in the comment to the solution shown in
It is observed that in this fourth embodiment, based on the possible combinations of materials that can be used for the central layer 30 and for the innermost layers 41,42, the two frames 44,54 can be glued to the corresponding surfaces 21′-30′, 21″-30″ by means of butyl glue. Moreover, in this embodiment also, a specific chemically inert gas such as those already indicated above can also be advantageously provided inside the interspaces 11,12.
In this fifth embodiment also, the central portion 6 also defines a single interspace 11, preferably containing air, between the two outermost portions 4,5. This interspace 11 is, in this case also, defined by means of spacer means corresponding to those described above as a comment to the first and third embodiments to which reference should be made for economy of description.
It is observed that in this embodiment, a specific chemically inert noble gas (argon, krypton or xenon for example), which use is made possible for sealing of the first interspace 11, on the one hand, and for the use of glass or plastic material for the central layer 30 and for the first inner surface 21′ of the first portion 4, on the other hand, is preferably but not exclusively provided inside the first interspace 11. However, given the permeability characteristics of the cementitious material constituting the second portion 5, air is preferably provided in the second interspace 12.
The different embodiments of the above-described panel advantageously allow the set aims and objects to be fully achieved. In particular, with respect to known solutions, the panel according to the invention has major acoustic and thermal insulation capacities while maintaining light transparency properties between the two outermost faces.
Number | Date | Country | Kind |
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MI2014A000910 | May 2014 | IT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/060886 | 5/18/2015 | WO | 00 |